UTC — Coordinated Universal Time

Coordinated Universal Time is the world's time standard. It never changes for daylight saving, which makes it the neutral reference used in aviation, computing, science and international coordination.

Every other zone is expressed as an offset from UTC. New York in winter is UTC−5, India is UTC+5:30 all year, and Kathmandu is UTC+5:45.

If you are scheduling something across many countries, stating the time in UTC removes ambiguity entirely.